Im having trouble with my truck getting hot.Its a 77 20R truck.When im driving it gets hot.I can stop and let it idol and it cools back down (the Temp.)Does anybody have ant ideal what it might be?
Three thoughts (guesses): 1. make sure you didn't install thermostat upside down? 2. I once went through three brand new OEM thermostats in a row that were bad; must have been a bad batch. Check (or replace) the thermostat. 3. Are you using OEM hoses or an aftermarket hose with the wire coil in it? I've read that the wire coils can cause problems and that you should OEM hoses.
Everyone has covered everything I have done and thought of... 1. Thermostat ( In backwards and testing BEFORE replacing are new thoughts ). 2. Fan ( You visually see, yes? Broken blades ?) 3. Blocked radiator - Is the front of the radiator clean of debris, bugs, dirt? 4. Flush radiator - Flush interior. I used a three day Prestone flush to remove calcium and scale build-up inside the radiator AND engine ports. 5. Hoses - Might there be a small leak or crack that is evaporating before you see? Any indications of scales on engine from leak? 6. Radiator Fluid Level - Is the level constant or are you losing fluid? Also check radiator cap. The overflow/anti-freeze fluid reservoir : is it open and spilling out from the engine over heating? If so, what color is the fluid? Clear or rusty? 7. Blown headgasket - Possible! Just happened to me! Did a full post and got lots of responses. Check oil for water. This is VERY common since the head is aluminum and block is Iron. The different metals head and and block heat and expand at different rates. The gasket between them bears the brunt and breaks. Machinist who shaved my head says he sees this once a week! http://www.toyotaminis.com/forum/en...et-back-onto-camshaft-without-removing-20897/ There's also additive that you can add to radiator that cools the engine up to 20 degrees. I've never used it, but am considering it. That MIGHT address the symptoms of what is happening with your engine. But finding the actual issue is really more important. Please respond and share the knowledge and experience.
Also saw this post and seems to be applicable. Air Bubbles - You might have pockets of air in the engine. A reverse flush might address the problem. See the last post in the following post for a method to eliminate air bubbles. http://www.toyotaminis.com/forum/engine-drivetrain-59/84-22r-heating-6599/
yup!! what busted knuckles said, air pockets are a possibility. Happened to me once on a 99 beetle! Radiator outlet broke clean off, purchased new rad, filled with water to test overheated within 1 minute. Did as Busted said, flushed it one way, than the other, and in a reverse direction, one last time. That did the trick!!! l2ewind!